Wireless technology, such as that associated with computers (especially laptop computers) is rapidly emerging with new standards that bring new capabilities, higher bandwidths, and new challenges to the market. The industry is rapidly adopting these new standards and incorporating such standards into products. For example, the standard configuration on IBM ThinkPads was 0.11 b in 2003, 0.11 b/g in 2004, 0.11 a/b/g in 2005, and 0.11 a/b/g/n for 2006 and beyond.
For system producers, the incorporation of such technologies is normally reasonably straightforward. The technologies are “backward compatible”, in that they fall back to accommodate 0.11 n, 0.11 a, 0.11 g, and 0.11 b, respectively. Therefore the PC OEMs (original equipment manufacturers) are comfortable in quickly incorporating the newer technologies since customers are provided with “investment protection” (or protection against obsolescence) all the same. Thus, while today the overwhelmingly prevalent installed base is 802.11 b, the machines being sold support 0.11 b, 0.11 g, and 0.11 a nonetheless.
It is presently accepted that in the future customers will be able to upgrade a network by upgrading the access points and then clients as rollouts continue. However, a problem has been recognized in connection with using multiple 802.11 n channels in a location where there are a small number of available channels. An industry group known as TGn Sync has proposed 40 MHz channels in order to meet 802.11 n specifications. However (as discussed above), 802.11 n is, by definition, backwards compatible with 802.11 a, 802.11 b, and 802.11 g, which are defined to use 20 MHz wide channels.
In cases where 802.11 n is used in places where there is a limited number of non-overlapping channels (such as the worldwide 2.4 GHz ISM band, which has a maximum of three 20 MHz non-overlapping channels, or where only a limited number of 5 GHz channels are available, such as in much of Asia & Latin America) there will clearly be interference between multiple 802.11 n Access Points. While two 40 MHz channels can be used in the 2.4 GHz spectrum, these will overlap. In areas where the overlapping channels are present, collisions can easily occur and transmissions will be disrupted when devices on the two channels transmit at the same time. The current WLAN specifications do not provide a method for operating in an overlapping channel environment.
Accordingly, a need has been recognized in connection with facilitating the use of multiple 802.11 n channels in environments that have hitherto not been conducive to the same.